From c58675a5a0c7d80028f3fe0002c8fc72cc616520 Mon Sep 17 00:00:00 2001
From: LukeMathWalker <contact@palmieri.com>
Date: Sat, 13 Mar 2021 10:08:54 +0000
Subject: [PATCH] Use a SQL transaction.

---
 src/routes/subscriptions.rs | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/src/routes/subscriptions.rs b/src/routes/subscriptions.rs
index 20355f5..b1ac42f 100644
--- a/src/routes/subscriptions.rs
+++ b/src/routes/subscriptions.rs
@@ -5,7 +5,7 @@ use actix_web::{web, HttpResponse};
 use chrono::Utc;
 use rand::distributions::Alphanumeric;
 use rand::{thread_rng, Rng};
-use sqlx::PgPool;
+use sqlx::{PgPool, Transaction, Postgres};
 use std::convert::TryInto;
 use uuid::Uuid;
 
@@ -43,14 +43,16 @@ pub async fn subscribe(
         .0
         .try_into()
         .map_err(|_| HttpResponse::BadRequest().finish())?;
-    let subscriber_id = insert_subscriber(&pool, &new_subscriber)
+    let mut transaction = pool.begin().await.map_err(|_| HttpResponse::InternalServerError().finish())?;
+    let subscriber_id = insert_subscriber(&mut transaction, &new_subscriber)
         .await
         .map_err(|_| HttpResponse::InternalServerError().finish())?;
     // We are swallowing the error for the time being.
     let subscription_token = generate_subscription_token();
-    store_token(&pool, subscriber_id, &subscription_token)
+    store_token(&mut transaction, subscriber_id, &subscription_token)
         .await
         .map_err(|_| HttpResponse::InternalServerError().finish())?;
+    transaction.commit().await.map_err(|_| HttpResponse::InternalServerError().finish())?;
     let _ = send_confirmation_email(
         &email_client,
         new_subscriber,
@@ -98,10 +100,10 @@ pub async fn send_confirmation_email(
 
 #[tracing::instrument(
     name = "Saving new subscriber details in the database",
-    skip(new_subscriber, pool)
+    skip(new_subscriber, transaction)
 )]
 pub async fn insert_subscriber(
-    pool: &PgPool,
+    transaction: &mut Transaction<'_, Postgres>,
     new_subscriber: &NewSubscriber,
 ) -> Result<Uuid, sqlx::Error> {
     let subscriber_id = Uuid::new_v4();
@@ -115,7 +117,7 @@ pub async fn insert_subscriber(
         new_subscriber.name.as_ref(),
         Utc::now()
     )
-    .execute(pool)
+    .execute(transaction)
     .await
     .map_err(|e| {
         tracing::error!("Failed to execute query: {:?}", e);
@@ -126,10 +128,10 @@ pub async fn insert_subscriber(
 
 #[tracing::instrument(
     name = "Store subscription token in the database",
-    skip(subscription_token, pool)
+    skip(subscription_token, transaction)
 )]
 pub async fn store_token(
-    pool: &PgPool,
+    transaction: &mut Transaction<'_, Postgres>,
     subscriber_id: Uuid,
     subscription_token: &str,
 ) -> Result<(), sqlx::Error> {
@@ -141,7 +143,7 @@ pub async fn store_token(
         subscription_token,
         subscriber_id
     )
-    .execute(pool)
+    .execute(transaction)
     .await
     .map_err(|e| {
         tracing::error!("Failed to execute query: {:?}", e);